Can't see any image library pictures in 'create gallery'

I'm pulling my hair out trying to create a gallery on wordpress's free, standard online version. Any help would be very welcome. I upload photos to the media library, can see them in the media library, but when I try to create a gallery there are no images shown to choose from. To the best of my knowledge I haven't installed any plugins or done anything else that should interfere. I tried changing the theme, switching from the standard one to another 'recommended' one.

Previously I got around this by uploading images and then pasting the image's library url into the post and displaying that way, but it doesn't look great and is tedious. For what it's worth, I've recently re-installed a different (better) version of windows and switched from chrome to ie10, and the only constant is that this feature didn't work properly before and still doesn't now.